This is what I have come up with:
Timer Modules 1 & 2 come as a coplete kit including small PCB. They are about £4 each from Rapid
The timer modules are a lot more flexible than the standard types you see on Amazon and Ebay and can be set to differnt modes by adjusting two potentiometers. These are also used to set the timing. Because the timers come in bits they should help modifications for other projects. They are all through hole which is once again good for mods. The relay can only handle 3A compared to the 10A for the common prebuilt types, but I would feel more confortable for this application with a more substantial relay anyway and would probably have sugessted using the relay specified here for the original timer module. I could imagine igniters being a rather demanding load. If the igniter turns out to be a begine load of up to an Amp, Q1 and associated componedts could be omitted and the relay on the timer board used.
The relay is an automotive 30A type which is rugged, but quite cheap at around £3.50
The transistor is a medium power bipolar costing about £0.50
Building should be quite simple: the boards are amall and simple to stuff as all components are thru hole. The relay is a standard auto tye with flanges for mouting with bolts and the terminals are standard slip-on crimp type male contacts. That just leaves Q1 which also bolts down, with an insulating washer, so the only lose component is the resistor.
This is how it works (should work)
TM2 has a delay of 10 seconds and TM1 2 seconds (these times can be adjusted)
When the switch is pushed both timers change state. TM1 provides the 2 second pulse for the igniter via relay 1.
TM 2 prevents frurther triggering of TM1 and hence prevents further igniter operation.
When TM2 resets, triggering by S1 is enabled again.
At least that is the theory.
The circuit for the controller is shown below along with the shematic for the timer modules. The instructions for building the timer modules is also attached.